A new computerized production testing facility for measuring loudspeaker drive units and systems is described. Unit and sound impulse responses are measured directly in a semi-anechoic environment, and a fast Fourier transform analyzer is used to calculate and display the corresponding frequency response. All frequency response curves are stored on a magnetic disk and special software routines, which enable drive units to be matched for shape and sensitivity to within 0.5 dB, are described. The precautions necessary for the design of the measuring environment and the equipment in order to achieve the desired accuracy are discussed.
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